Portable ventilating appliances

ABSTRACT

A portable ventilating appliance has a free-standing housing containing a fan wheel, filter and electric driving motor. The fan wheel has a vertical axis of rotation and is disposed above the filter which is in the form of a hollow body. A drive shaft passing through the filter couples the fan wheel to the motor which is resiliently located in the housing below the filter, the motor being suspended at the bottom end of the shaft which has a single supporting bearing adjacent the fan wheel.

nite States Patent 1191 Boehm [451 'Nov. 26, 1974 PORTABLE VENTILATINGAPPLIANCES Inventor: Hans-Georg Boehm, Kronberg,

Germany Assignee: Braun Aktiengesellschaft, Frankfurt,

Germany Filed: Feb. 6, 1973 Appl. No.: 329,985

[30] Foreign Application Priority Data Feb. 14, 1972 Austria 1159/72U.S. Cl 55/387, 55/389, 98/33 A Int. Cl 801d 53/04, F24f 13/00 Field ofSearch 98/33 A; 55/74, 75, 294,

[56] References Cited UNITED STATES PATENTS 3,090,490 5/1963 Yocuk55/387 3,116,990 Duer .f. 55/294 3,252,270 4/1966 Pau et al 55/743,501,897 3/1970 Van Helden et al 55/74 3,516,232 6/1970 Gilbertson55/387 3,750,370 8/1973 Brauss et al. 55/316 Primary Examiner-Charles N.Hart Attorney, Agent, or Firm-Cushman, Darby & Cushman [5 7] ABSTRACTlocated in the housing below the filter, the motor being suspended atthe bottom end of the shaft which has a single supporting bearingadjacent the fan wheel.

4 Claims, 2 Drawing Figures lll PORTABLE VENTILATING APPLIANCESBACKGROUND OF THE INVENTION The invention relates to a portableventilating appliance with a housing and a fan wheel driven by anelectric motor which displaces the air through at least one Forhousehold use, such appliances must be of simple construction in orderto keep manufacturing costs low and, if at all possible, should requireno attention. Whilst the weight must be low, great stability isdemanded. Particularly with free-standing appliances, it is desirablefor the air to exit above the standing surface at a definite minimumdistance to prevent stirring up dust, displacement of papers, etc.Difficulties are then met with in housing the filter in such a way thatit is easily accessible, large in area and effective.

SUMMARY OF THE INVENTION The object of the invention is to provide aportable vetilating appliance of the type mentioned above and such thatthe requirements referred to can be met whilst, especially with small,handy dimensions, a high filter performance and, with small standingsurface, high stability can be obtained.

To this end, according to the invention, the fan wheel is arranged witha vertical axis of rotation in the housing above the filter, which isdeveloped as an upright, preferably prismatic hollow body, and theelectric motor is located beneath the filter and is coupled to the fanwheel by a vertical drive shaft.

The arrangement of the comparatively heavy motor in the lower part ofthe housing provides stability for the appliance; the standing surfaceequally is only small, since the motor, filter and fan wheel arearranged above one another. This also enables the air exit to be at adesired distance from the standing surface. The individual componentscan be accomodated in the housing and assembled and removed withoutgreat expense, which is particularly important when cleaning or changingthe filter.

The construction and assembly of the appliance can be still furthersimplified if, developing the idea behind the invention, the drive shaftonly supported by the housing in the region of the fan wheel and theelectric motor is resiliently suspended in the housing. Only a singlebearing is then required between the housing and the rotating parts, sothat all problems of ensuring hearing alignment are dispensed with. Thedriving shaft bearing is usefully developed as a self-aligning bearingto permit trouble free mounting even with the drive shaft tilted.

In a preferred development of the invention, the filter is a hollowprismatic, preferably cylindrical, cartridge of a loosely pressed, in agiven case stuck or sintered, adsorption medium. for example activatedcarbon or zeolite, in which a supported cage or wires or a wire cloth isinserted. Such a cartridge is sufficiently rigid by itself, so that aspecial container as is required with a granular filter structure can bedispensed with.

After being in use for a certain time, absorption filters becomeincreasingly ineffective, and they must be reactivated. Usually thefilters are then removed and subjected to a heat treatment generally atthe manufacturers works. To avoid this removal and to facilitate therebythe handling and assembly of the appliance, in a particularlyadvantageous exploitation of the construction of the filter cartridgesaccording to the invention, the supporting cage of the cartridge is usedas an electrical heating element. For reactivating the adsorptionfilter, the cartridge is heated up by means of this heating resistancewithout dismantling the appliance.

In addition, a folded paper filter can be placed on the side of thefilter cartridge where the air enters to trap floating materials whichmust be kept away from the carbon filter.

BRIEF DESCRIPTION OF THE DRAWINGS Further advantages and possibleapplications of the invention are mentioned in the following descriptionof a preferred embodiment with reference to the accompanying drawings,in which:

FIG. 1 is a considerably simplified lengthwise section through afree-standing vetilating appliance of cylindrical shape, and

FIG. 2 is a section along the line II II of FIG. 1.

DESCRIPTION OF THE PREFERRED EMBODIMENT The ventilating applianceillustrated is enclosed by a housing 1, which in this example isdeveloped essentially as a free-standing upright hollow cylinder. In theupper part of the housing there is mounted a radialfiow fan wheel 2connected to a vertical drive shaft 3 which is mounted, beneath the fanwheel, in a bearing 4 supported by the housing. An-electric motor 5which drives the fan wheel 2 is located in a bottom section of housing 1and suspended at the lower end of the shaft 3. The motor is locatedradially in the housing 1 by springs 6.

A central compartment of the housing 1 is occupied by a hollowcylindrical filter cartridge 7, consisting for example of sinteredactivated carbon which is sintered on to a supporting cage 8 formed fromwires. A folded paper filter 9 is arranged around this filter cartridge.As indicated by the broken lines, the housing 1 is pierced at theperimeter to form a grille in the region of the filter and the fan wheelso as to allow the passage of air.

The radial fan 2 sucks the air from all round the appliance as shown byarrows into the fan housing. It first passes through the folded paperfilter 9, where floating particles are removed, and then through thefilter cartridge 7; here, in particular, gaseous and steam-typeimpurities, such as odours, are separated out. The air is sucked out ofthe cylindrical hollow space 10 inside the filter cartridge upwards intothe fan wheel and blown out radially.

The wires forming the filter supporting cage 8 can be connected by aswitch (not illustrated) with the current supply to motor 5 and theythen form an electrical heating element by means of which the filtercartridge 7 can be heated for regeneration at regular intervals, i.e.,to free it from the adsorbed gaseous and steamtype substances. Thisswitch is usefully interlocked with the switch (not illustrated) in themotor current circuit, so that the cartridge cannot be heated during thenormal operation of the appliance.

The paper filter can be chemically prepared or impregnated, for examplewith oxidising substances, such as transition metallic oxides, whichhave a deodorising effect. The activated carbon filter could also beimpregnated in this way.

By the arrangement of the heaviest component, namely the motor 5, in thelower part of the housing 1, the relatively tall ventilating applianceis given good stability on the supporting surface 1 l;-the standingsurface area required is, however, only small. The single bearing 4suffices for centralising and guiding all rotating parts, with the driveshaft 3 freely aligned by the resilient suspension of the motor 5. Thebearing 4 could be secured elastically to permit a swinging motion ofthe drawing shaft or to simplify its alignment, for example by linkingthe bearing 4 in known fashion with the housing by an elastic diaphragm(not illustrated. To change the filter components, the top wall of thehousing 1 is removed and the fan wheel 2 withdrawn from the drive shaft3.

Instead of a radial-flow fan as illustrated, an axialflow fan can beused to impel the air from the interior of the filter cartridge upwards.Other housing and filter shapes are possible. However, hollow prismatic,especially hollow cylindrical, filter cartridges are preferably used.Instead of one cartridge several cartridges can be used, for examplearranged alongside one another in a row or cluster, in order to increasethe, while still providing a filtering wall or barrier, with optimumdimensions for the housing.

Among adsorption filters, usable within the framework of the invention,are to be counted also electrostatic filters which have the capacity toseparate out odorous materials which, as is known, are adherent tofloating particles.

1 claim:

1. A portable ventilating appliance comprising a freestanding uprightcolumnar housing having lower peripheral openings and upper openings, afan wheel mounted at the upper end of the housing for rotation about avertical axis within the housing, a filter mounted in said housing belowthe fan wheel and comprising a filter wall around said axis so that airis drawn by the fan wheel through said lower openings and the filterwall and expelled through said upper openings, an electric driving motorfor the fan wheel positioned in the housing below the filter and asubstantially vertical drive shaft passing through the filter within thefilter wall and coupling the motor to the fan wheel.

2. A ventilating appliance according to claim 1, the filter comprisingan adsorption medium and an electrical heating element the form of asupporting wire cage in and for said medium, whereby the filter may beheated for regeneration.

3. A portable ventilating appliance comprising an up right cylindricalhousing perforated for the. circulation of air therethrough, a fan wheelmounted for rotation about a vertical axis within the housing, a filterin the form of an upright hollow body mounted in the housing below thefan wheel so thatair circulated through the housing by the fan wheelpasses through the filter, an electric driving motor for the fan wheelpositioned in the housing below the filter, and a substantially verticaldrive shaft which couples the motor to the fan wheel and passes throughthe hollow filter, the drive shaft being supported by the housing onlyin the region of the fan wheel and the electric motor being resilientlysuspended in the housing.

'4. A ventilating appliance according to claim 3, wherein the bearing ofthe drive shaft is a self-aligning bearing.

1. A portable ventilating appliance comprising a freestanding uprightcolumnar housing having lower peripheral openings and upper openings, afan wheel mounted at the upper end of the housing for rotation about avertical axis within the housing, a filter mounted in said housing belowthe fan wheel and comprising a filter wall around said axis so that airis drawn by the fan wheel through said lower openings and the filterwall and expelled through said upper openings, an electric driving motorfor the fan wheel positioned in the housing below the filter and asubstantially vertical drive shaft passing through the filter within thefilter wall and coupling the motor to the fan wheel.
 2. A ventilatingappliance according to claim 1, the filter comprising an adsorptionmedium and an electrical heating element in the form of a supportingwire cage in and for said medium, whereby the filter may be heated forregeneration.
 3. A portable ventilating appliance comprising an uprightcylindrical housing perforated for the circulation of air therethrough,a fan wheel mounted for rotation about a vertical axis within thehousing, a filter in the form of an upright hollow body mounted in thehousing below the fan wheel so that air circulated through the housingby the fan wheel passes through the filter, an electric driving motorfor the fan wheel positioned in the housing below the filter, and asubstantially vertical drive shaft which couples the motor to the fanwheel and passes through the hollow filter, the drive shaft beingsupported by the housing only in the region of the fan wheel and theelectric motor being resiliently suspended in the housing.
 4. Aventilating appliance according to claim 3, wherein the bearing of thedrive shaft is a self-aligning bearing.